Surgical instrument

ABSTRACT

A surgical instrument including a body member which houses a motor and removably mounts an interchangeable head member. The body member includes a socket part which interlockingly receives an insert part of the head member in any selected rotative position relative to the head part. Means are provided for coupling the drive shaft of the motor to a driven shaft in the head member upon insertion of the insert part of the head member into the socket part of the body member.

United States Patent 'Appl. No.

Donald D. Keller Bourbon, Ind.;

Richard D. Robinson, Bryan, Ohio 791,582

Jan. 16, 1969 Apr. 13, 1971 Orthopedic Equipment Company Bourbon, Ind.

Inventors Filed Patented Assignee SURGICAL INSTRUMENT 10 Claims, 5 Drawing Figs.

US. Cl 287/119,

32/26 Int. Cl F16d1/10 Field of Search 287/2, 119,

103, 126; 287/1; 32/26; 279/(Inquired) References Cited UNITED STATES PATENTS 4/1955 Swisher et a1 287/119X 2,492,815 12/1949 Robinson,.lr 287/103X 2,719,688 10/1955 Seifert 287/126X 2,987,334 6/1961 Wendling 287/119 3,287,031 11/1966 Simmons et 287/103X Primary ExaminerDavid J. Williamowski Assistant Examiner-Wayne L. Shedd Attarney-0ltsch & Knoblock ABSTRACT: A surgical instrument including a body member WhlCh houses a motor and removably mounts an interchangeable head member. The body member includes a socket part which interlockingly receives an insert part of the head member in any selected rotative position relative to the head part. Means are provided for coupling the drive shaft of the motor to a driven shaft in the head member upon insertion of the insert part of the head member into the socket part of the body member.

PATENTEU APR] 3m! 3574.374

sum 2 OF 2 INVENTORS DONALD D. KELLER BY 4- RICHARD D. ROBINSON 6M 15 MAM ATTORNE Y5 SURGICAL INSTRUMENT SUMMARY OF THE INVENTION This invention relates to a power driven surgical instrument, and particularly to a coupling between a body member which houses a motor, and a head member which houses means for transmitting power from said motor to a surgical tool carried by the head member. The head member is releasably attached to the body member and preferably includes an insert part which is slidably received within a socket part of the body member. The insert part of the head member is interlocked within the socket part of the body member by means of a detent which is carried by the insert part and which is recieved within a recess in the socket part. The motor housed within the body member includes a drive shaft having an end portion which extends into the, bore of the socket part. The power transmitting means housed within the head member includes a driven shaft having an end portion which extends approximately to the end face of the insert part and which has an axial bore therein. The end portion of the drive shaft is noncircular in cross section and includes parts which are complementally received within grooves in the bore-defining surface of the driven shaft with a slide fit when the insert part of the head member is inserted into and is interlocked within the socket part of the body member.

The head member of this invention can be quickly coupled to and uncoupled from the instrumemts body member. This permits the surgeon to change from one type of head member, such as a high-speed head, to another type head member, such as a low-speed head, as required, with only minimum time and effort required. Additionally, the insert and socket parts of the surgical instrument of this invention are designed to permit the insert part to be coaxially interlocked with the socket part in any selected rotative position. This adjustment feature allows the surgeon, when using a head member carrying a cutting burr or similar surgical tool which is positioned at an angle to the axis of the head member, to selectively position the body member so that the body member can be comfortably held during use of the instrument. Also this adjustment feature makes the instrument adaptable for use by either left-handed or right-handed surgeons. The coupling parts utilize a novel resilient member which serves to press against locking detents of the coupling and to absorb vibrations at the joint.

Accordingly, it is an object of this invention to provide a surgical instrument having a body member housing a drive motor, and an interchangeable head member carrying a surgical tool and including means for transmitting power from the motor to said tool, with a coupling by means of which the head member can be rapidly and simply coupled to and uncoupled from the body member by simple manipulation and without requiring the use of tools.

It is another object of this invention to provide a coupling for a surgical instrument having a body member housing a motor and an interchangeable coaxial head member attached to the body member for transmitting power from the motor to a cutting tool attached to the head member, in which the head member can be positioned in any selected rotative position upon the body member and the coupled parts are held firmly connected by yielding locking means which absorb relative vibration of the coupled parts.

Other objects of this invention will become apparent upon a reading of the inventions description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of one embodiment of the surgical instrument of this invention;

FIG. 2 is an axial sectional view of the surgical instrument illustrated in FIG. 1; 7

FIG. 3 is an enlarged detailed fragmentary sectional view of that portion of the surgical instrument indicated by broken line brackets in FIG. 2;

FIG. 4 is an enlarged fragmentary perspective exploded view of component members of the surgical instrument illustrated in FIG. 1 shown uncoupled;

FIG. 5 is a perspective end view of one component illustrated in FIG. 4 as viewed in the direction of the arrows 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the instrument here illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described in order to best explain the principles of the invention and its application and practical use, to thereby enable others skilled in the art to best utilize the invention.

Referring to FIG. 1 and FIG. 2, the surgical instrument illustrated is preferably adapted for hand-held use and includes a body member 10 and an interchangeable head member 12 which is releasably attached to body member 10.

Body member 10 is preferably of an elongated substantially cylindrical configuration and houses a motor 20 which is preferably of the rotary vane type. Body member 10 has internal passages 18 therein which preferably extend from the motor chamber 21 to the aft end 14 of member 10. A flexible conduit 16 is connected to aft end 14 of body member 10 and serves to transfer a compressed gas, such as nitrogen or air, from a source, such as a storage tank (not shown) to passages 18 in body member 10 where the gas can flow in motor chamber 21 and actuate motor 20. A lever 22 is pivotally attached at one end to aft end 14 of body member 10 and extends longitudinally forwardly therefrom. Lever 22 serves to actuate a valve member 24 which regulates the flow 1 of compressed gas in passages 18 to the motor 20. A second valve 26 is positioned within body member 10 and communicates with passages 18 therein. Valve 26 is actuated by a knob 28 and serves to control the direction of flow of gas in motor 20, thereby enabling the surgeon to reverse the motor.

Head member 12 houses gear means 30 which may include a planetary gear system having an output shaft 32 connected by means of bevel gears 33 to a laterally directed rotatable split-sleeve 34 which, in cooperation with a collet (not shown), is adapted to receive and hold various surgical tools, such as burrs, screwdrivers, drills, cutters and other attachments commonly utilized in orthopedic surgery. It is to be understood that in some constructions of the head member 12, the sleeve 34 may be coaxial with output shaft 32 of gear means 30. The surgical instrument thus far described is of a construction well known in the art.

This invention has particular application to a quick connect-disconnect coupling which serves to couple body member 10 to head member 12 in a power-transmitting relationship. Body member 10 includes an outer housing 38 preferably having a forward end portion or socket part 40 which has a coaxial bore 42 (FIG. 4) therein. Referring to FIG. 3 and FIG. 4, bore 42 is preferably defined by a tubular wall 44 and a rear inset transverse or end wall 46. The inner surface of tubular wall 44 is interrupted by a recess such as a circumferential annular groove 48 which is preferably forwardly spaced from end wall 46. That portion of the inner surface of tubular wall 44 which extends forwardly or outwardly of groove 43 is interrupted by a plurality of longitudinally extending substantially parallel slots 50 which are equally spaced apart and extend rearwardly from the forward end face 52 of body member 10 and terminate adjacent to and equally spaced from groove 48. Each slot 50 is defined in part by an end face 51 which is preferably with radius to facilitate insertion of lock elements 82 of the insert part of the head member 12 into the body member.

Motor 20 in'body member 10 includes a drive shaft 56 which preferably extends with clearance through a central aperture 58 in end wall 46 of the body member and projects coaxially in bore 42. Drive shaft 56 preferably includes a forward end part 60 whose end surface is slightly inset relative to the plane of the outer edge of end face 52 of body member 10 and which preferably is square or triangular in cross section, having flat side faces 62. Each side face 62 of motor shaft end part 60 preferably includes a forward marginal part 64 which is beveled.

Head member 12 includes an outer housing 65 preferably carrying a rear end portion or insert part 68 which projects endwise therefrom and has an outer diameter slightly less than the inner diameter of tubular wall 44 of housing member 10, so as to permit the complemental sliding engagement of the projecting end part 653 within longitudinal bore 42 of the body member. Part 68 has a coaxial bore 70 and an annular coaxial slot or deep groove 76 formed therein which defines an outer annular part 71 and a concentric annular inner part '73. Outer annular part 71 has a plurality of radial bores 78 extending therethrough which are preferably equally angularly spaced apart and which communicate with annular groove 76. A plurality of locking elements 82 are disposed within groove 76 with a portion of each element 82 extending through bore 78 and projecting laterally beyond the outer surface of insert part 68. A ring 86 of resilient material, such as rubber, is seated in and substantially fills groove 76 and is compressed at the parts thereof located between the inner annular part 73 and the elements 82. Each element 82 includes a part positioned within groove 76 which has a maximum outer dimension which exceeds the diameter of its receiving bore 78. The inner annular part 73 is interrupted by recesses 84 caused by development of transverse bores 78 to assist in retaining the resilient ring 86 within slot 76. A portion 85 of the ring 86 projects endwise beyond the rear end face 74 of part 68. Projection 90 or a plurality of projections 90 protrude laterally from part 68. Projection 90 is located adjacent to and forward of and longitudinally aligned with a bore 78 and may comprise the head of a screw which has been threaded into part 68.

Gear means 30 (FIG. 2) housed within head member 12 includes a pinion or driven shaft 92 (FIG. 3) having a rear end part 96 which extends coaxially and with clearance into bore 70 in part 68, and which terminates approximately at the plane of end face 74 of part 68. End part 96 of pinion shaft 92 has an axial bore 98 formed therein. Bore 98 has an enlarged coaxial outer end portion 100. Bore 98, 100 is interrupted by a plurality of equal angularly spaced, longitudinally extending V-shaped grooves 102 which preferably extend the full length of bore 98, as best shown in FIG. 5. There are preferably eight grooves 102, but the number of such grooves may vary proportionately to and constitutes a multiple of the number of faces 62 of shaft end 60. Each groove 102 is of such a size and is so spaced from the other grooves that end part 60 of drive shaft 56 can be inserted into bore 98 with each longitudinal edge 104 between adjacent faces 62 of shaft end part 60 being complementally received within a groove 102.

To connect interchangeable head member 12 to body member 10, the insert part 62 of head member 12 is inserted into bore 42 of body member 10 with protruding part 90 positioned in one of the slots 50. Insert part 68 is then forced axially in bore 42 of body member 10; causing elements 82, as they engage radii 51 of groove 50 to be cammed into lateral bores 78 until they snap r seat in annular groove 48 by the pressure of the resilient ring 86 thereagainst. With elements 82 seated in groove 48 and projection 90 recieved within slot 50 in body member 10, head member 12 is restrained from axial separation from body member and is also prevented from rotation relative thereto. Portion 35 of resilient ring 86 projects beyond end face 74 and engages end wall 46 of member 10 to thereby damp motor and tool vibration which might otherwise occur between the head and body members.

Nearly simultaneously with the insertion of insert part 68 of head member 12 into bore 42 of body member 10, the end part 60 of drive shaft 56 is received within bore 98 of pinion shaft 92 with the tapered end parts 64 of the drive shaft 56 entering enlargement 100 of bore 98 and then entering the smaller inner part of the bore, with the edges 104 of the drive shaft received within grooves 102 of bore 98 of the driven shaft. Any misalignment of the edges 104 of the drive shaft 56 with respect to grooves 102 of bore 98 when the drive shaft first enters bore 98 is corrected as the tapered parts 64 of the drive shaft enter bore 98 and engage the sidewalls of the bore. The head may be separated from the body by manual pull thereon.

In the form shown the various angular positions that head member 12 can assume relative to body member 10 are dependent upon the number of slots 50 in forward end portion 40 (FIG. 2) of the body member. Although it has been found that six slots 50 will provide a satisfactory range of adjustment for the head member, the number of slots may vary depending upon the desired range of adjustment and size of the instrument. Alternately, by omitting projection any selected rotation position of the head on the body may be provided. Although it is preferable to have an equal number of projections 90 and elements 82, a single projection could be utilized to prevent rotational movement of the head member 12 relative to the body member 10.

We claim:

1. In a surgical instrument including a body member housing a motor having a drive shaft and an interchangeable head member removably attached to said body member and housing a driven shaft for transmitting power from said motor to a surgical tool carried by said head member, the improvement wherein one of said head member and said body member includes a socket part having a longitudinal bore defined by a tubular wall, the inner face of said tubular wall having a recess, the other of said head member and body member including an insert complementally received within the longitudinal bore of said socket part and having a radial aperture in registry with the recess in said socket part, said drive and driven shafts including end parts coaxial relative to said socket and insert parts and interfitting in powertransmitting engagement upon insertion of said insert part into the longitudinal bore of said socket part, a locking element slidably disposed within said radial aperture and having an outermost position in which a portion of said element seats in the recess of said socket part, and means carried by said insert part for resiliently biasing said element into its said outermost position.

2. The instrument of claim 1 wherein the inner face of said tubular wall is cylindrical and said tubular wall has a longitudinal slot in its inner face which extends inwardly from the end of said socket part, and said insert part includes a lateral projection spaced longitudinally from said radial aperture and slidably fitting in said longitudinal slot.

3. The instrument of claim 2 wherein said tubular wall has a plurality of projection-receiving longitudinal slots therein.

4. The instrument of claim 3 wherein said longitudinal slots are equally spaced apart and said insert part includes one or a plurality of lateral projections equally spaced apart and each slidably fitting within a longitudinal slot in said tubular wall.

5. The instrument of claim 1 wherein the recess of said socket part is a circumferential groove and said insert part has a plurality of radial apertures equally spaced apart and each receiving a locking element having a portion seating in said circumferential groove.

6. The instrument of claim 1 wherein said insert part has a circumferential groove in its end which communicates with said radial aperture therein, and said means biasing said locking element includes a resilient ring disposed within said groove and engaging said element.

7. The instrument of claim 1 wherein the end part of one of said drive and driven shafts has multiple side faces each having its forward margin beveled, and the end part of the other of said drive and driven shafts has an axial bore therein which interlockingly receives said first-mentioned shaft end part.

8. The instrument of claim 7 wherein said axial bore is interrupted by a plurality of equal spaced longitudinal V- shapcd grooves each adapted to receive a corner edge between adjacent side faces of said first-mentioned shaft end part, said V-shaped grooves being of a number constituting a multiple of the number of said comer edges.

9. In a surgical instrument including a body member housing a motor having a drive shaft and an interchangeable head member removably attached to said body member and housing a driven shaft for transmitting power from said motor to a surgical tool carried by said head member, the improvement wherein one of said head member and said body member includes a socket part having a longitudinal bore defined by a tubular wall, the inner face of said tubular wall having a circumferential groove, the other of said head member and body member including an insert part complementally received within the longitudinal bore of said socket part and having a plurality of radial apertures equally spaced apart and each in registry with the groove in said socket part, each radial aperture receiving a locking element having a portion seating in said groove, means carried by said insert part for resiliently biasing each element portion into said groove, said tubular wall having a plurality of longitudinal slots in its inner face which extend inwardly from the end of said socket part and terminate forwardly of said groove, said longitudinal slots being equally spaced apart, said insert part having one or a plurality of lateral projections each spaced forwardly of and in substantial longitudinal alignment with a radial aperture and slidably fitting in a said longitudinal slot, and said drive and driven shafts interfitting in powertransmitting engagement upon insertion of said insert part into the longitudinal bore of said socket part.

10. In a surgical instrument including a body member housing a motor having a drive shaft and an interchangeable head member removably attached to said body member and housing a driven shaft for transmitting power from said motor to a surgical tool carried by said head member, the improvement wherein one of said head member and said body member includes a socket part having a longitudinal bore defined by a tubular wall, the inner face of said tubular wall having a recess, the other of said head member and body member including an insert part complementally received within the longitudinal bore of said socket part and having a radial aperture in registry with the recess in said socket part, a locking element slidably disposed within said radial aperture and having an outermost position in which a portion of said element seats in the recess of said socket part, means carried by said insert part for resiliently biasing said element into its said outermost position, said insert part having a circumferential groove in its end which communicates with said radial aperture therein, said socket part including an inset end wall defining in part said longitudinal bore therein, said means biasing said element including a resilient ring disposed within said groove, said ring having a portion projecting beyond the end face of said insert part and engaging said inset end wall, and said drive and driven shafts interfitting in powertransmitting engagement upon insertion of said insert part into the longitudinal bore of said socket part. 

1. In a surgical instrument including a body member housing a motor having a drive shaft and an interchangeable head member removably attached to said body member and housing a driven shaft for transmitting power from said motor to a surgical tool carried by said head member, the improvement wherein one of said head member and said body member includes a socket part having a longitudinal bore defined by a tubular wall, the inner face of said tubular wall having a recess, the other of said head member and body member including an insert complementally received within the longitudinal bore of said socket part and having a radial aperture in registry with the recess in said socket part, said drive and driven shafts including end parts coaxial relative to said socket and insert parts and interfitting in powertransmitting engagement upon insertion of said insert part into the longitudinal bore of said socket part, a locking element slidably disposed within said radial aperture and having an outermost position in which a portion of said element seats in the recess of said socket part, and means carried by said insert part for resiliently biasing said element into its said outermost position.
 2. The instrument of claim 1 wherein the inner face of said tubular wall is cylindrical and said tubular wall has a longitudinal slot in its inner face which extends inwardly from the end of said socket part, and said insert part includes a lateral projection spaced longitudinally from said radial aperture and slidably fitting in said longitudinAl slot.
 3. The instrument of claim 2 wherein said tubular wall has a plurality of projection-receiving longitudinal slots therein.
 4. The instrument of claim 3 wherein said longitudinal slots are equally spaced apart and said insert part includes one or a plurality of lateral projections equally spaced apart and each slidably fitting within a longitudinal slot in said tubular wall.
 5. The instrument of claim 1 wherein the recess of said socket part is a circumferential groove and said insert part has a plurality of radial apertures equally spaced apart and each receiving a locking element having a portion seating in said circumferential groove.
 6. The instrument of claim 1 wherein said insert part has a circumferential groove in its end which communicates with said radial aperture therein, and said means biasing said locking element includes a resilient ring disposed within said groove and engaging said element.
 7. The instrument of claim 1 wherein the end part of one of said drive and driven shafts has multiple side faces each having its forward margin beveled, and the end part of the other of said drive and driven shafts has an axial bore therein which interlockingly receives said first-mentioned shaft end part.
 8. The instrument of claim 7 wherein said axial bore is interrupted by a plurality of equal spaced longitudinal V-shaped grooves each adapted to receive a corner edge between adjacent side faces of said first-mentioned shaft end part, said V-shaped grooves being of a number constituting a multiple of the number of said corner edges.
 9. In a surgical instrument including a body member housing a motor having a drive shaft and an interchangeable head member removably attached to said body member and housing a driven shaft for transmitting power from said motor to a surgical tool carried by said head member, the improvement wherein one of said head member and said body member includes a socket part having a longitudinal bore defined by a tubular wall, the inner face of said tubular wall having a circumferential groove, the other of said head member and body member including an insert part complementally received within the longitudinal bore of said socket part and having a plurality of radial apertures equally spaced apart and each in registry with the groove in said socket part, each radial aperture receiving a locking element having a portion seating in said groove, means carried by said insert part for resiliently biasing each element portion into said groove, said tubular wall having a plurality of longitudinal slots in its inner face which extend inwardly from the end of said socket part and terminate forwardly of said groove, said longitudinal slots being equally spaced apart, said insert part having one or a plurality of lateral projections each spaced forwardly of and in substantial longitudinal alignment with a radial aperture and slidably fitting in a said longitudinal slot, and said drive and driven shafts interfitting in power-transmitting engagement upon insertion of said insert part into the longitudinal bore of said socket part.
 10. In a surgical instrument including a body member housing a motor having a drive shaft and an interchangeable head member removably attached to said body member and housing a driven shaft for transmitting power from said motor to a surgical tool carried by said head member, the improvement wherein one of said head member and said body member includes a socket part having a longitudinal bore defined by a tubular wall, the inner face of said tubular wall having a recess, the other of said head member and body member including an insert part complementally received within the longitudinal bore of said socket part and having a radial aperture in registry with the recess in said socket part, a locking element slidably disposed within said radial aperture and having an outermost position in which a portion of said element seats in the recess of said socket part, means carried by said insert part fOr resiliently biasing said element into its said outermost position, said insert part having a circumferential groove in its end which communicates with said radial aperture therein, said socket part including an inset end wall defining in part said longitudinal bore therein, said means biasing said element including a resilient ring disposed within said groove, said ring having a portion projecting beyond the end face of said insert part and engaging said inset end wall, and said drive and driven shafts interfitting in power-transmitting engagement upon insertion of said insert part into the longitudinal bore of said socket part. 